JPS61244746A - Cleavable can member - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a tearable can member made of thin metal sheet,
a pair of predetermined tear lines laterally limiting the tear strip; a tongue constructed as a separate sheet metal member and welded to the tear strip at the ends within the weld; It is of the type that is provided with a predetermined tear initiation line extending on the tear strip between the weld and the free end of the tongue at least close to the predetermined tear line on both sides.

In a can part known from the prior art (DE 10 17 042), the tongue is stamped in the initial state together with a flat blank. The surface of the tongue extends beyond one longitudinal edge of the blank. Two predetermined tear lines which laterally limit the tear strips as well as a predetermined tear initiation line connecting these predetermined tear lines with each other are formed near the other longitudinal edge of the blank (by pressing ). Next is the blank.

The two longitudinal edges are rolled onto each other and subsequently welded to form a seam. As a result, a cylindrical can body is obtained. Finally, a complete can is produced from the can body by closing it by edging both end faces of the can body together with the lid or bottom. To split the can, insert an opener into the tongue and roll the opener against the nearest rim.

With these known cans, it is not always possible, especially for an inexperienced consumer, to tear off the tear strip as completely as desired on site.

It is not uncommon for the dehiscence strip to break already in the area of the longitudinal edge or just behind it, since a convergent crack is formed starting from the tongue, which leads to the planned dehiscence line in the circumferential direction. This is because it can be understood between. The consumer is forced to continue opening the can using a tool not originally intended for opening the can, risking injury from the cut sheet metal.

A tearable can member of the type described in Changtou has been proposed in order to ensure that the tearing process is carried out more reliably. In the can member, the planned tear initiation line is a predetermined tear line that extends across the tear strip in a perpendicular direction and, if necessary, extends slightly above two predetermined tear lines that laterally limit the tear strip. Consists of open lines.

The can part according to this proposal splits satisfactorily if the tongues are precisely positioned on the tearing strip during welding so that the predetermined tearing initiation line is located in the immediate vicinity of the weld. However, if the weld is far away from or covers the planned tear start line due to manufacturing errors, the planned tear start line will not play its role or will function only insufficiently. When the tongue is rolled up with the opener, the tearing strip is first bent and then the crack is rapidly run over the entire width between the predetermined tearing lines which laterally limit the tearing strip. Manufacturing errors that can complicate the tearing process and result in an unfavorable relative position between the planned tear start line and the weld are caused by press-forming of the planned tear start line, punching out during the tongue piece, and Obtained from handling and welding errors. If we try to keep all these errors so small that they do not adversely affect the dehiscence process even in the case of an unfavorable overlap of these errors, it becomes relatively expensive to carry out the above working steps. requires such a method and apparatus.

Problem to be Solved by the Invention It is an object of the present invention to solve the problem of the invention in that the tearing process is not made significantly more difficult by the presence of relatively large manufacturing tolerances of the kind mentioned above. It is possible to improve the can member.

In a can part of the type mentioned at the outset, the predetermined tear initiation line is part of the area of a number of predetermined tear lines formed in the tear strip below the tongue, and the weld partially covers this area. This means that it is completely covered.

Implementation mode It is advantageous if the

It is advantageous if the area is circular or square, since in general it can be ensured that the above-mentioned tolerance error has approximately the same magnitude in all directions in the plane of the area.

In an advantageous embodiment of the invention, the zones are defined by concentric predetermined tear lines. Such a predetermined tearing line can be formed using a die, and can be produced by turning the die in a simple manner.

However, a circular predetermined tear line has the advantage that it has a particularly low tendency to break and thereby render the can part unusable when subjected to bending and/or stretching loads.

Bending loads occur, for example, when a flat blank can member is rolled into a cylindrical can body.

In addition, bending loads appear to be increased when filled cans are deformed by careless handling; stretching loads, which can be problematic in the area of pre-planning, tearing, and opening lines, are particularly important for cans that have first been rolled into a cylindrical shape. Occurs when a member is expanded into a cuboid or truncated pyramid or truncated cone edge.

Instead of an area consisting of concentric circles, it consists of a number of constant fission X-rays extending perpendicularly to the tearing strip, and advantageously supplemented by a number of predetermined tearing lines extending longitudinally of the tearing strip. Also suitable are areas where

In another embodiment, the area has multiple intersecting diagonal predetermined tear lines.

According to Japanese Patent Application No. 60-210371, the tongue of the tearable can member is welded to the end 1. It has a thickened part in the shape of an arrow pointing towards the free end of the tongue. In combination with this feature, the present invention is characterized in that the tip of the arrow-shaped thickened portion is located above the center of the area defined by the planned tear initiation line and a number of other planned tear lines. It can be constructed particularly advantageously.

the tongue has a triangular recess on the lower surface above the area;
It is advantageous if the recess is such that it limits the weld to an arrow-shaped part of the area.

In this way, the forces induced when winding up the tongue with the opener are concentrated in the center of the area, so that the crack starts from the center of the area and gradually spreads towards the edges of the weld, resulting in a split strip. reaching the planned longitudinal dehiscence line which laterally limits the

The can part 10 shown in the exemplary drawings initially has two longitudinal edges 12, 14.
is a rectangular blank with . The can member 10 is rolled into a cylindrical rim as shown by the circular curve in FIG. 1 during the manufacturing process of cans. Continued two longitudinal edges 12,
14 are welded together. The seam may be a pin seam or a pad seam as shown in FIGS. 1 and 2, and a knotted seam may be made by laser welding.

The can member 1o has a pair of parallel planned tear lines 16. The planned tearing line is carved so as to be perpendicular to the longitudinal edges 12 and 14.

Laterally delimiting tear strips 18 extend over the entire circumference of the final can. A tongue 20 is welded to the tear strip 18. According to FIG. 1 and FIG. 2, an opener 22 can be inserted into this tongue 20 and the tongue 20 and then the entire tear strip 18 can be wound up. At this time, Ausina 22 has two edged greens 24. Stay on one side and rotate. A rim 24 connects each of the rectangular can parts according to FIG. One additional vertical planned tear line parallel to the planned tear line 16 (first
3) or two (FIGS. 5 to 8), the longitudinal predetermined tear line likewise extends around the entire circumference of the can.

The tear strip 18 is engraved with a region 28 consisting of a number of predetermined tear lines, in any case one of which is the predetermined tear line when the tongue 20 is wound. Serves as a starting line 30.

The area 28 is arranged at a sufficient distance from the two longitudinal edges L2.14 so that it is not subject to fluctuations in the seam of the sheet metal that may occur during welding of these longitudinal edges. Area 2
The width of 8 may be equal to the width of tearing strip 1' 80. However, it only extends over the distance shown in the figure. The zone 28 can advantageously be produced using a die after cutting out the predetermined tear line 16 in the can part 10 in its flat state.

The area 28 can also be constituted by a different, in particular straight, predetermined tearing line. The straight planned tear line, for example according to FIGS. 5 and 6, extends at right angles to the lateral planned tear line 16, and the area 28 according to FIG. It has an additional predetermined tear line extending parallel to the tear line 16. As shown in FIGS. 7 and 8, the area 28 can also be constituted by predetermined tearing lines that intersect diagonally with each other. In all of the examples shown in FIGS. 5-8, the area 28 may be more or less precisely square or circular.

The tongue 20 has a free end 32 for insertion of the orthina 22, which can be easily bent away from the can part 1o, for example with a fingernail. The end of the other tongue piece 20 to be welded to the can member 10 has a thickened portion 34 .

In the illustrated embodiment, the thickened portion 34 is produced by bending the arrow-shaped end section outwards so that its tip 3G faces the free end 32 when the tongue 20 is punched out. .

A recess 38 is carved into the lower surface of the tongue piece 20. The recess 38 likewise has the shape of an arrow and is directed toward the free end 32 but smaller than the thickened portion 34 . The recess 38 is correspondingly bounded by an arrow-shaped zone 40 on the side facing the free end 32 of the tongue 20; the zone 40 has a Wazuffle-like surface structure that is slightly more prominent than the other underside of the tongue. have.

In each of the configurations shown in FIGS. 3, 5 through 8 of zone 28, tongue 20 is welded to tear strip 18 with tip 36 positioned as precisely as possible above the center of zone 28. be arranged to be located.

During welding, under the action of the crimping force generated by the welding electrodes, a particularly good current flow occurs between the area 28 and the arrow-shaped zone 4o structured in a Wazful-like manner, so that the weld 42 is shaped like an arrow. A zone 40 of the form occurs over area 28 . The weld 42 is thus approximately arrow-shaped, but extends beyond one area 28 and thus does not reach the two predetermined tear lines that laterally limit the tear strip 18. The weld 42 covers an additional longitudinal predetermined tear line located between the lateral predetermined tear lines 16 .

Effects of the Invention In the present invention, the dimensions of the zones and the distances between the planned tearing lines constituting the zones are based on simple tests and are determined as follows with respect to the thickness of the sheet metal and other properties of the can part and the tongue. can be harmonized so that the
This means that even if all errors overlap unfavorably, the weld partially covers the area consisting of the planned tear line, but only partially.
At least one predetermined tear line will always be covered by the weld, and this predetermined tear line may first cause the tear strip to hinge when the tongue is wound up in the opener; It is then achieved that the weld is located at as small a distance as possible from the weld.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a canned can when it starts to split; Figure 2 is a partially enlarged view of Figure 1; Figure 3 is a view of the part of the can member to which the tongue piece is welded; FIG. 4 is a diagram showing various embodiments. 10...Can member, 12.14...Vertical edge, 16...
Planned tearing line, 18... Tearing strip, 20... Tongue piece, 2
2... Opener, 24... Rim with edge, 26... Lid or bottom, 28... Area, 30... Scheduled tearing start line, 32... Free line, 34... Thick part, 36...
・Tip part, 38... recess, 40... zone, 42・
··welded part. Fig, 1

Claims (1)

[Claims] 1. A tearable can member made of a thin metal plate, including a pair of planned tear lines (16) laterally restricting tear strips (18).
a tongue (20) constructed as a separate sheet metal member and welded at its end to the splitting strip (18) within the weld (42); Tongue piece (2
0) with a planned tearing start line (30) extending on the tearing strip (18) between it and the free end (32) at least close to the planned tearing line (16) on both sides. In the case where the planned tearing start line (30) is formed in the tearing strip (18) below the tongue (20), a number of planned tearing line areas (
28) and the weld (42) is part of this area (
28) A tearable can member, characterized in that it partially covers the can member. 2. Can member according to claim 1, wherein the area (28) extends over 2/3 to 4/5 of the width of the tear strip (18). 3. Can member according to claim 1 or 2, wherein the area (28) is circular. 4. Claim 1, wherein the area (28) is square
Can member according to item 1 or 2. 5. The can member according to claim 3, wherein the area (28) is constituted by concentric predetermined tearing lines. 6. Any one of claims 1 to 4, wherein the area (28) has a number of predetermined tear lines extending perpendicularly to the tear strip (18). Can parts described in section. 7. Can member according to claim 6, wherein the area (28) additionally has a number of predetermined tear lines extending in the longitudinal direction of the tear strip (18). 8. Claims 1 to 4, wherein the area (28) has a number of predetermined tearing lines that intersect diagonally with each other.
The can member described in any one of the preceding paragraphs. 9. The tongue (20) has a thick walled portion (34) in the shape of an arrow pointing toward the free end (32) of the tongue (20) at the end to which the tongue (20) is welded. Can member according to any one of claims 1 to 8, wherein the tip (36) of the flesh (34) is arranged above the center of the area (28). 10. The tongue (20) has a triangular recess (38) on the underside above the area (28), the recess (38) aligning the weld (42) with the arrow of the area (28). 10. A can member according to claim 9, wherein the can member is adapted to be limited to a shaped portion.